#1. Why are cellulose membrane filters frequently selected for filtration of aqueous pharmaceutical solutions?
#2. Which property of cellulose membrane filters ensures predictable microbial retention?
#3. In sterile filtration of buffers for aseptic processing, cellulose acetate membranes are preferred mainly because they:
#4. Which pharmaceutical activity most commonly uses mixed cellulose ester (MCE) membrane filters?
#5. What is the primary filtration mechanism of cellulose membrane filters?
#6. Which pore size of cellulose membrane filter is typically used for microbial reduction in pharmaceutical liquids?
#7. A formulation scientist wants minimal loss of a low-dose API during filtration. Which membrane property is most critical?
#8. Why are cellulose membrane filters commonly used in QC laboratories?
#9. Which statement best explains the regulatory acceptance of cellulose membrane filters?
#10. In water system monitoring, cellulose membrane filters are primarily used to:
#11. Which limitation must be considered when selecting cellulose membrane filters?
#12. Why do cellulose membrane filters support low-pressure filtration operations?
#13. Which pharmaceutical document should include cellulose membrane filter details?
#14. Which membrane type is generally avoided for product filtration due to high binding?
#15. From a GMP perspective, cellulose membrane filters are best described as:
#16. Which feature of cellulose membrane filters helps preserve biological product integrity?
#17. In pharmaceutical filtration, cellulose membrane filters mainly act as:
#18. Why are cellulose membrane filters often described as “silent quality enablers”?
#19. During a regulatory audit, it is observed that cellulose membrane filters used for buffer filtration are changed without updating batch records. What is the primary GMP concern?
#20. During sterility testing, inconsistent microbial recovery is observed using mixed cellulose ester membranes. What should an auditor expect as a corrective action?
#21. A QC laboratory filters protein samples using nitrocellulose membranes, leading to low assay results. What is the root cause most likely identified by QA?
#22. An inspector asks how the company ensures that cellulose membrane filters do not impact product quality. Which response best demonstrates GMP compliance?
#23. During an audit, it is found that cellulose membrane filters are reused after cleaning. What is the most critical audit concern?
#24. An auditor reviews water monitoring records and notes membrane filtration results without filter lot numbers. What is the classification of this issue?
#25. A change from cellulose acetate to regenerated cellulose membrane was implemented without change control. What would an auditor most likely cite?
#26. During inspection, filters are stored in an open area without protective packaging. What is the main GMP risk?
#27. An audit finds that no justification exists for selecting cellulose membrane filters over synthetic membranes. What is the expected regulatory response?
#28. A deviation report shows reduced filtration flow but no investigation into membrane condition. What audit deficiency does this indicate?
#29. An auditor questions why integrity testing is not performed on cellulose membrane filters. Which response is most acceptable?
#30. During inspection, cellulose membrane filters are found missing from the Bill of Materials. What is the regulatory impact?
#31. A sterile buffer batch fails microbial limits, and filtration records show excessive pressure during filtration. What is the most likely auditor conclusion?
